Back to all

Idle Talk about Engines (Causes of Rough Engine Idling)

January 1, 2021

When you slow down at stoplight, your vehicle's idle should be smooth as silk.  But what happens when the engine is missing or idling roughly? That's your engine's way of telling you, "Hey, I've got something wrong with me and if you don't get someone to find out what it is, I may not start the next time you turn the key."

You can help your service facility if you can describe the problem in detail.  Here's a list of things to make a note of:

  • When is the problem happening, when the engine is cold or when it's been running for a while?
  • Does the rough idling occur when I'm accelerating or when I'm going at a steady speed?
  • Does it happen at high speeds?  Does it happen low speeds? Does it happen at both?

Make sure you describe the problem in as much detail because it will help a technician diagnose the problem.

One of the first things they'll check is how the spark plugs are firing.  Modern iridium plugs are supposed to last a long, long time.  But they CAN eventually wear out.  Inspecting the firing end can help the technician figure out the root of the problem.  Corroded or worn out spark plug wires, too, can contribute to an idling irregularity. 

There are other potential problem spots, too.  The technician may check the ignition coil, timing piston rings, valves and cylinder walls. 

If the mixture of air and fuel isn't correct, that may affect how smooth your vehicle is running.  Your service facility is equipped with diagnostic equipment that helps them pinpoint the problem.  Once that idle is smoothed out to the way it used to be, you'll be the smoothest operator on the road.

Tuffy Tire & Auto Perrysburg
27140 Oakmead Dr.
Perrysburg, Ohio 43551
419-873-8330

More articles from Tuffy Perrysburg

A Not-So-Straight Story (Vehicle Pulls to One Side)

February 22, 2026

A vehicle should travel straight down a straight road with the steering wheel centered. But time and travel can take their toll and soon you may find your vehicle pulling to the left or right. Those are not good signs and should be taken care of fairly quickly. One thing that you should note is... More

Let?s Shift Gears (Transmission Fluid Replacement)

February 15, 2026

If you have a vehicle with an automatic transmission, you probably never think about gear shifting. When motor vehicles were invented, all of them had to be shifted manually. But that wonderful self-shifting transmission, referred to these days as simply an automatic, changed everything. Automa... More

If the Shoe Fits (Brake Shoe Replacement [Rear])

February 8, 2026

When it comes to brakes on your vehicle, we all know how important it is to keep them working well because they are vital safety equipment. After all, if you cant slow down and stop, you cant drive safely. While many vehicles use what are called disc brakes, theres another type of brakes that ... More